Originally Posted by TryHard

Afraid it's forced by regulations. Basically it's to do with specing the nose to be a certain height (safety grounds), but not doing the same for the chassis bulkheads...which to get most airflow under the car to the floor, you want as high as possible. Combine that with cross-section sizes for the bulkheads, all add's up to the platypus noses.
Some do look better than others (Torro rosso for example), but only Macca went the full hog and lowered the whole nose... but they use a different front end concept to most with a snow shovel under the nose cone to ram air underneath.